压敏电阻基本知识.doc

压敏电阻的型号及选用方法 SJ1152-82部颁标准中压敏电阻器的型号命名分为四部分，各部分的含义见表1。表1 压敏电阻器的型号命名及含义一部分：主称第二部分：类别第三部分：用途或特征第四部分：序号字母含义字母含义字母含义M敏感电阻器Y压敏电阻器无普通型用数字表示序号，有的在序号的后面还标有标称电压通流容量或电阻体直径、标称电压、电压误差等。D通用B补偿用C消磁用E消噪用G过压保护用H灭弧用K高可靠用L防雷用M防静电用N高能型P高频用S元器件保护用T特殊型W稳压用Y环型Z组合型第一部分用字母 “M” 表示主称为敏感电阻器。第二部分用字母 “Y” 表示敏感电阻器为压敏电阻器。第三部分用字母表示压敏电阻器的用途的特征。第四部分用数字表示序号，有的在序号的后面还标有标称电压、通流容量或电阻体直径、电压误差、标称电压等。例如：MYL1-1（防雷用压敏电阻器）MY31-270/3（270V/3kA普通压敏电阻器）M敏感电阻器M敏感电阻器Y压敏电阻器Y压敏电阻器L防雷用31序号1-1序号270标称电压为270V3通流容量为3kA压敏电阻是一种以氧化锌为主要成份的金属氧化物半导体非线性电阻元件；电阻对电压较敏感，当电压达到一定数值时，电阻迅速导通。由于压敏电阻具有良好的非线特性、通流量大、残压水平低、动作快和无续流等特点。被广泛应用于电子设备防雷。主要参数：1、残压：压敏电阻在通过规定波形的大电流时其两端出现的最高峰值电压。2、通流容量：按规定时间间隔与次数在压敏电阻上施加规定波形电流后，压敏电阻参考电压的变化率仍在规定范围内所能通过的最大电流幅值。3、泄漏电流：在参考电压的作用下，压敏电阻中流过的电流。4、额定工作电压：允许长期连续施加在压敏电阻两端的工频电压的有效值。而压敏电阻在吸收暂态过电压能量后自身温度升高，在此电压下能正常冷却，不会发热损坏。压敏电阻的不足：（1）寄生电容大 压敏电阻具有较大的寄生电容，一般在几百至几千微微法的范围。在高频信号系统中会引起高频信号传输畸变，从而引起系统正常运行。/P（2）泄漏电流的存在 压敏电阻的泄漏电流指标既关系到被保护电子系统的正常运行，又关系到压敏电阻自身的老化和使用寿命。压敏电阻的损坏形式：（1）当压敏电阻在抑制暂态过电压时能量超过其额定容量时，压敏电阻会因过热而损坏，主要表现为短路、开路。MYL表示防雷型压敏电阻MYE表示高负荷型压敏电阻,也有厂家用MYT表示通用型，MYL表示防雷型.选用方法(一般情况）:1、压敏电压值应大于实际电路的电压峰值，一般为：U1mA =K1/K2K3 UCU1mA - 压敏电压UC - 电路直流工作电压（交流时为有效值）K1 - 电源电压波动系数，一般取1.2 K2 - 压敏电压误差,一般取0.85K3 - 老化系数,一般取0.9交流状态下，应将有效值变为峰值，即扩大2倍，实际应用中可参考此公式通过实验来确定压敏电压值。/P2、通流量实际应用中，压敏电阻器所吸收的浪涌电流应小于压敏电阻的最大峰值电流，以延长产品的使用寿命。压敏电阻的检测。用指针式万用表的R1k挡测量压敏电阻两引脚之间的正、反向绝缘电阻，均为无穷大，否则，说明漏电流大。若所测电阻很小，说明压敏电阻已损坏，不能使用。压敏电阻是一种限压型保护器件。利用压敏电阻的非线性特性，当过电压出现在压敏电阻的两极间，压敏电阻可以将电压钳位到一个相对固定的电压值，从而实现对后级电路的保护。压敏电阻的主要参数有：压敏电压、通流容量、结电容、响应时间等。压敏电阻的响应时间为ns级，比空气放电管快，比TVS管稍慢一些，一般情况下用于电子电路的过电压保护其响应速度可以满足要求。压敏电阻的结电容一般在几百到几千pF的数量级范围，很多情况下不宜直接应用在高频信号线路的保护中，应用在交流电路的保护中时，因为其结电容较大会增加漏电流，在设计防护电路时需要充分考虑。压敏电阻的通流容量较大，但比气体放电管小。压敏电阻的压敏电压（min(U1mA）、通流容量是电路设计时应重点考虑的。在直流回路中，应当有：min(U1mA) (1.82)Udc，式中Udc为回路中的直流额定工作电压。在交流回路中，应当有：min(U1mA) (2.22.5)Uac，式中Uac为回路中的交流工作电压的有效值。上述取值原则主要是为了保证压敏电阻在电源电路中应用时，有适当的安全裕度。在信号回路中时，应当有：min(U1mA)(1.21.5)Umax，式中Umax为信号回路的峰值电压。压敏电阻的通流容量应根据防雷电路的设计指标来定。一般而言，压敏电阻的通流容量要大于等于防雷电路设计的通流容量。压敏电阻主要可用于直流电源、交流电源、低频信号线路、带馈电的天馈线路。压敏电阻的失效模式主要是短路，当通过的过电流太大时，也可能造成阀片被炸裂而开路。压敏电阻使用寿命较短，多次冲击后性能会下降。因此由压敏电阻构成的防雷器长时间使用后存在维护及更换的问题。在消费类电子产品中，为了追求较小的安装面积，压敏电阻做成叠层型，称为Multi-layer Varistor(MLV),其结构与叠层型的瓷片电容（MLCC）完全相同，只是叉指电极间的材料不是普通的陶瓷电介质，而是ZnO压敏材料。也因为如此，MLV都是具有一定的电容特性的，甚至可以根据需要定制具有某种容量的MLV，这对于防护设计中兼顾EMI设计是非常有利的。由于做成叠层结构后，MLV的电极寄生电感非常小，因此其反应速度与TVS不相伯仲，甚至比某些采用Bonding结构的TVS的速度还要快。电流容量上，得益于叠层结构，MLV的通流能力也要比相同体积的TVS大得多。那么，MLV是不是就没有缺点呢，也不是MLV的钳位特性曲线不如TVS陡峭，不能实现精确的钳位；MLV在多次大电流冲击后，性能会出现一定程度的退化，主要表现是漏电流增大，钳位电压有所变化。不过，如果MLV仅用于ESD防护，上述两个缺点对防护效果的影响是很小的。这也是为什么MLV能在手机、数码相机等领域大行其道。7D系列压敏电阻 型号规格压敏电压最大允许使用电压 限制电压(8/20S) 能量耐量(J) 通流量 ( 8/20S ) 静态功率电容量(参考值)已获得认证及号码 V1mA(v)ACrms(v)DC(v)Vc(v)Ip(A)10/1000S2ms1次冲击(kA)2次冲击(kA)(W)1kHz( pF)ULCSAVDECQCHEL-7D821K657-82751067013351057421.751.250.2553HEL-7D781K657-82648564012901053401.751.250.2555HEL-7D751K657-82546061512401055401.751.250.2557HEL-7D681K612-74842056011201053401.751.250.2560HEL-7D621K558-68238550510251048351.751.250.2570HEL-7D561K504-6163504609201046321.751.250.2575HEL-7D511K459-5613204188421045321.751.250.2580HEL-7D471K423-5173003857751042301.751.250.2590HEL-7D431K387-4732753507101040281.751.250.25100HEL-7D391K351-4292503206501035251.751.250.25105HEL-7D361K324-3962303003951032231.751.250.25125HEL-7D331K297-3632102755501029211.751.250.25130HEL-7D301K270-3301952505051026191.751.250.25135HEL-7D271K243-2971752254551024171.751.250.25150HEL-7D241K216-2641502003951021151.751.250.25165HEL-7D221K198-2421401803601019141.751.250.25190HEL-7D201K185-2251301703401018131.751.250.25240HEL-7D181K162-1981151503001015111.751.250.25330HEL-7D151K135-1659512525010139.01.751.250.25490HEL-7D121K108-1327510020010107.51.751.250.25670HEL-7D101K90-1106085165108.56.01.751.250.25860HEL-7D820K74-905065135107.05.01.751.250.25930HEL-7D680K61-7540561352.54.53.60.50.250.02970HEL-7D560K50-6235451102.53.42.70.50.250.021,050HEL-7D470K42-523038932.52.82.30.50.250.021,150HEL-7D390K35-432531772.52.41.90.50.250.021,450HEL-7D330K30-362026652.52.01.60.50.250.021,800HEL-7D270K24-301722532.51.61.30.50.250.022,200HEL-7D220K20-241418432.51.31.10.50.250.022,800HEL-7D180K15.5-211114382.51.10.90.50.250.023,5007D系列压敏电阻产品尺寸(mm) 已获得认证 Dmax9Hmax11Lmin25A150.020.67D系列压敏电阻厚度Tmax(mm) 180K-680K5.0621K-681K 7.0820K-201K5.0751K-821K 7.5221K-331K5.5361K-471K6.0511K-561K6.55D系列压敏电阻 型号规格压敏电压最大允许使用电压 限制电压(8/20S) 能量耐量(J) 通流量 ( 8/20S ) 静态功率电容量(参考值)已获得认证及号码 V1mA(v)ACrms(v)DC(v)Vc(v)Ip(A)10/1000S2ms1次冲击(kA)2次冲击(kA)(W)1kHz( pF)ULCSAVDECQCHEL-5D681K612-7483855601120525198006000.168HEL-5D621K558-6823855051025524188006000.175HEL-5D561K504-616350460920523178006000.180HEL-5D511K459-561320418842522168006000.185HEL-5D471K423-517300385810521158006000.190HEL-5D431K387-473275350745520158006000.1100HEL-5D391K351-429250320675517128006000.1105HEL-5D361K324-396230300620516118006000.1125HEL-5D331K297-363210275575515108006000.1130HEL-5D301K270-33019525052551398006000.1135HEL-5D271K243-29717522547551288006000.1150HEL-5D241K216-264150200415510.57.58006000.1165HEL-5D221K198-24214018038059.06.08006000.1190HEL-5D201K185-22513017035559.06.08006000.1240HEL-5D181K162-19811515032057.55.58006000.1330HEL-5D151K135-1659512526056.54.58006000.1490HEL-5D121K108-1327510021054.53.58006000.1670HEL-5D101K90-110608517554.03.08006000.1860HEL-5D820K74-90506514553.52.58006000.1930HEL-5D680K61-75405615012.21.62501250.01970HEL-5D560K50-62354512311.81.32501250.011,050HEL-5D470K42-52303810411.51.12501250.011,150HEL-5D390K35-4325318611.20.92501250.011,450HEL-5D330K30-3620267311.10.82501250.011,800HEL-5D270K24-3017226010.90.72501250.012,200HEL-5D220K20-2414184810.70.52501250.012,800HEL-5D180L15.5-2111144010.60.42501250.013,5005D系列压敏电阻产品尺寸(mm) 已获得认证 =正在认证中Dmax7.5 Hmax9.5Lmin25A150.020.65D系列压敏电阻厚度Tmax(mm) 180K-680K5.0621K-681K 7.0820K-201K5.0221K-331K5.5361K-471K6.0511K-561K6.520D系列压敏电阻 型号规格压敏电压最大允许使用电压 限制电压(8/20S) 能量耐量(J) 通流量 ( 8/20S ) 静态功率电容量(参考值)已获得认证及号码 V1mA(v)ACrms(v)DC(v)Vc(v)Ip(A)10/1000S2ms1次冲击(kA)2次冲击(kA)(W)1kHz( pF)ULCSAVDECQCHEL-20D182K1620-198010001465297010010207201071.0220HEL-20D112K900-121068089518151006204401071.0450HEL-20D102K900-110062582516501005604001071.0500HEL-20D951K855-104557576515801005353801071.0550HEL-20D911K819-100155074515001005103601071.0600HEL-20D821K738-90251067013551004603251071.0700HEL-20D781K702-85848564012901004453151071.0750HEL-20D751K657-82546061512401004203001071.0850HEL-20D681K612-74842056011201004002901071.0900HEL-20D621K558-68238550510251003902801071.0950HEL-20D561K504-6163504609201003852771071.0970HEL-20D511K459-5613204188421003822731071.01,000HEL-20D471K423-5173003857751003502501071.01,050HEL-20D431K387-4732753507101003032151071.01,100HEL-20D391K351-4292503206501002751951071.01,180HEL-20D361K324-3962303003951002551801071.01,250HEL-20D331K297-3632102755501002281601071.01,300HEL-20D301K270-3301952505051002161481071.01,350HEL-20D271K243-2971752254551002101451071.01,400HEL-20D241K216-2641502003951002001401071.01,500HEL-20D221K198-2421401803601001801301071.01,800HEL-20D201K185-2251301703401001601151071.02,000HEL-20D181K162-198115150300100130901071.02,600HEL-20D151K135-16595125250100106751071.03,000HEL-20D121K108-1327510020010088601071.03,800HEL-20D101K90-110608516510072551071.04,800HEL-20D820K74-90506513510056501071.05,800HEL-20D680K61-754056135204944320.210,000HEL-20D560K50-623545110204136320.212,000HEL-20D470K42-52303893203430320.214,000HEL-20D390K35-43253177202825320.216,000HEL-20D330K30-36202665202421320.218,000HEL-20D270K24-30172253201917320.222,000HEL-20D220K20-24141843201614320.232,000HEL-20D180K15.5-21111438201312320.239,00020D系列压敏电阻产品尺寸(mm) 已获得认证 Dmax23Hmax25Lmin25A1100.02120D系列压敏电阻厚度Tmax(mm) 180K-680K5.0621K-681K 7.0820K-201K5.0751K-821K 7.5221K-331K5.5102K-122K8.0361K-471K6.0142K-162K 10511K-561K6.5182K 1214D系列压敏电阻 型号规格压敏电压最大允许使用电压 限制电压(8/20S) 能量耐量(J) 通流量 ( 8/20S ) 静态功率电容量(参考值)已获得认证及号码 V1mA(v)ACrms(v)DC(v)Vc(v)Ip(A)10/1000S2ms1次冲击(kA)2次冲击(kA)(W)1kHz( pF)ULCSAVDECQCHEL-14D182K1620-1980100014652970505103606.550.6120HEL-14D112K900-12106808951815503102206.550.6150HEL-14D102K900-11006258251650502802006.550.6180HEL-14D951K855-10455757651580502701906.550.6190HEL-14D911K819-10015507451500502551806.550.6200HEL-14D821K738-9025106701355502351656.550.6230HEL-14D781K702-8584856401290502251606.550.6230HEL-14D751K657-8254606151240502101506.550.6260HEL-14D681K612-7484205601120502001456.550.6290HEL-14D621K558-6823855051025501951406.550.6320HEL-14D561K504-616350460920501921386.550.6360HEL-14D511K459-561320418842501901366.550.6390HEL-14D471K423-517300385775501751256.550.6420HEL-14D431K387-473275350710501551106.550.6440HEL-14D391K351-429250320650501401006.550.6480HEL-14D361K324-39623030039550130906.550.6500HEL-14D331K297-36321027555050115806.550.6550HEL-14D301K270-33019525050550108786.550.6600HEL-14D271K243-2971752254555099706.550.6650HEL-14D241K216-2641502003955084606.550.6710HEL-14D221K198-2421401803605078556.550.6840HEL-14D201K185-2251301703405070506.550.6970HEL-14D181K162-1981151503005065426.550.61,030HEL-14D151K135-165951252505053386.550.63,000HEL-14D121K108-132751002005042306.550.63,100HEL-14D101K90-11060851655035256.550.63,400HEL-14D820K74-9050651355028206.550.63,900HEL-14D680K61-754056135102016210.14,700HEL-14D560K50-623545110101613210.15,600HEL-14D470K42-52303893101411210.16,500HEL-14D390K35-4325317710119.4210.17,500HEL-14D330K30-36202665109.57.9210.18,500HEL-14D270K24-30172253107.86.5210.110,000HEL-14D220K20-24141843106.35.3210.115,000HEL-14D180K15.5-21111438105.23.3210.118,00014D系列压敏电阻产品尺寸(mm) 已获得认证 Dmax17Hmax19Lmin25A17.50.020.814D系列压敏电阻厚度Tmax(mm) 180K-680K5.0621K-681K 7.0820K-201K5.0751K-821K 7.5221K-331K5.5102K-122K8.0361K-471K6.0142K-162K 10511K-561K6.5182K 1210D系列压敏电阻 型号规格压敏电压最大允许使用电压 限制电压(8/20S) 能量耐量(J) 通流量 ( 8/20S ) 静态功率电容量(参考值)已获得认证及号码 V1mA(v)ACrms(v)DC(v)Vc(v)Ip(A)10/1000S2ms1次冲击(kA)2次冲击(kA)(W)1kHz( pF)ULCSAVDECQCHEL-10D182K900-1102100014652970252471833.52.50.460HEL-10D112K900-11016808951815251551103.52.50.490HEL-10D102K900-11006258251650251401003.52.50.4100HEL-10D951K855-1045575765158025135953.52.50.4110HEL-10D911K819-1001550745150025130903.52.50.4120HEL-10D821K738-902510670135525110803.52.50.4130HEL-10D781K702-858485640129025105753.52.50.4130HEL-10D751K657-825460615124025105753.52.50.4130HEL-10D681K612-748420560112025100723.52.50.4140HEL-10D621K558-68238550510252597703.52.50.4160HEL-10D561K504-6163504609202592673.52.50.4180HEL-10D511K459-5613204188422592673.52.50.4180HEL-10D471K423-5173003857752585603.52.50.4190HEL-10D431K387-4732753507102580553.52.50.4220HEL-10D391K351-4292503206502570503.52.50.4240HEL-10D361K324-3962303003952565453.52.50.4260HEL-10D331K297-3632102755502558423.52.50.4280HEL-10D301K270-3301952505052554383.52.50.4290HEL-10D271K243-2971752254552549353.52.50.4330HEL-10D241K216-2641502003952542303.52.50.4360HEL-10D221K198-2421401803602539283.52.50.4390HEL-10D201K185-2251301703402535253.52.50.4430HEL-10D181K162-1981151503002532213.52.50.4470HEL-10D151K135-165951252502525183.52.50.41,300HEL-10D121K108-132751002002520153.52.50.41,500HEL-10D101K90-11060851652517123.52.50.41,700HEL-10D820K74-9050651352514103.52.50.42,100HEL-10D680K61-7540561355108.210.50.52,500HEL-10D560K50-62354511058.16.710.50.52,900HEL-10D470K42-5230389356.85.610.50.53,300HEL-10D390K35-4325317755.64.710.50.53,700HEL-10D330K30-3620266554.84.010.50.54,200HEL-10D270K24-3017225353.93.210.50.54,800HEL-10D220K20-2414